Effect of planting pattern on phonological characteristics and growth indices of safflower (Carthamus tinctorius L.) in rainfed conditions

To study the effect of planting pattern on phonological and physiological characteristics of safflower in rainfed conditions a field experiment was conducted in Shirvan-Chardvol in Ilam in 2008-2009 cropping seasons. The experiment was performed using factorial arrangement in randomized complete block design with three replications. Treatments included of three row spacing (30, 40 and 50 cm) and three plant spacing (10, 15and 20 cm). Results showed that differences between treatments were significant for all phonological characteristics except days to emergence. The lower row spacing and plant spacing had shorter days to heading, flowering and maturity as compared to higher row and plant spacing. Results also showed that in the lower row and plant spacing, plant canopy closed quickly. The highest LAI (2.1 and 2.1), CGR (2.1 and 2.3 g.m-2.day-1), TDM (437.4 and 421.1 g.m-2) and NAR (0.209 and 0.216 g.g-1.day-1) were obtained in 30 cm row spacing and 10 cm plant spacing in the early and mid growth stages, however, CGR and NAR indices were negative, because of plant shading and loss of older leaves. The 30 cm row spacing and 10 cm plant spacing had maximum LAI, CGR and TDM, hence, grain yield (1971 and 1730 kg.ha-1, respectively). It is concluded that increasing grain yield in safflower in rainfed conditions can be obtained through increasing total dry matter and improving physiological indices.